		.ORG 0100H
	
PPI:    LD      A,90H
		OUT     (07H),A
		IN      A,(04h)
LOOP:	OUT     (05H),A
	
	CALL	DELAY
		RLC		A
		JP      LOOP

DELAY:  LD      C,0FFH
LOOP1:  LD      B,0FFH
LOOP2:	DEC		B
		JP      NZ,LOOP2
		DEC     C
		JP 		NZ,LOOP1
		RET

